This invention pertains to systems for transferring ammunition for weapons, and more specifically, it pertains to ammunition transfer systems for weapons mounted on carriages.
Ships have been used as weapons platforms for centuries. In modern times, warships mounting major caliber guns are often used for heavy bombardment of targets on shore. The emphasis on design of warships in the past has often focused on mounting a relatively large number of guns on a single platform due to the high cost involved with building large ships with the capability of supporting even one major caliber weapon. It was possible for such a ship to maintain a high rate of fire overall due to the large number of weapons.
Warships of today are often used to support limited engagements in which it is necessary for the weapons to have pinpoint accuracy in order to minimize collateral damage to non-military targets, and to provide close fire support for troops on the ground. Due to the relatively high cost of weapons with the desired degree of accuracy, it is desirable to develop weapons with a high rate of fire so as to minimize the need for large numbers on a single platform.
Ammunition rounds for major caliber weapons normally comprise a projectile round, a propellant charge round and a primer round or other igniting means. Separate ammunition is a term that refers to systems in which the three rounds are separately provided and are combined at the weapon. The term semi-fixed ammunition refers to systems in which the primer and the propellant are packaged together, and the term fixed ammunition refers to systems in which all three rounds are packaged together. Ammunition rounds for major caliber guns are normally of the separate or semi-fixed ammunition type. In addition, other weapons may use ammunition rounds in the form of torpedoes, rockets or other precision guided munitions, either in a single package or as separate rounds. For the purposes of this application, the term ammunition round is used interchangeably to refer to complete ammunition rounds as well as any separate portion thereof.
Weapons are usually mounted in turrets or carriages on a warship, and the tube or barrel of the weapon is generally controllable in elevation as well as in azimuth, referred to as train. The term elevation axis refers to the axis about which the weapon rotates in elevation, and the term train axis refers to the axis about which the weapon rotates in azimuth. Ammunition rounds are normally supplied to the carriages from magazines located deep in the hull through one or more ammunition handling systems. Such ammunition handling systems are well known.
Examples of previous ammunition handling systems are described in U.S. Pat. No. 3,218,930 to Girouard, et. al., U.S. Pat. No. 3,122,967 to Johnson, et. al., U.S. Pat. No. 4,457,209 to Scheurich et al., and U.S. Pat. No. 4,481,862 to Wiethoff, et. al., each of which is hereby fully incorporated herein by reference. In each of these systems, ammunition is supplied to the gun by a method known in the art as xe2x80x9coff-axis loadingxe2x80x9d, meaning that the ammunition rounds are supplied vertically to the carriage with a hoist located along an axis offset from the train axis of the gun.
A simplified diagram of a common type of off-axis loading system is depicted in FIG. 7. Off-axis loading is desirable in part because it allows a system to use multiple hoists and multiple gun cradles, thereby improving the rate of fire from that achievable with an on-axis loading system. Since the azimuth of the gun breech and cradle varies with the azimuth of the weapon in an off-axis loading system, however, a complex mechanism is required to receive the ammunition round from the off-axis hoist, transfer it the distance from the hoist to the cradle of the weapon, and align it with the breech so it can be loaded into the weapon. The necessity to xe2x80x9cfollowxe2x80x9d the train motion of the weapon makes the firing rate of the weapon dependant on the azimuth of the weapon, and thus can cause a significant negative impact on the rate of fire at certain azimuths.
What is needed is an off-axis loading type ammunition transfer system that enables a constant rate of fire at all weapon azimuths.
The present invention includes an ammunition transfer system for an off-axis loaded weapon, wherein the rate of ammunition transfer and the consequent rate of fire of the weapon is independent of the azimuth angle of the weapon. The benefits of off-axis loading are accordingly provided, without the degradation of the weapon rate of fire at certain weapon azimuths. In a preferred embodiment, the invention is a carrier assembly having a rotor with a plurality of ammunition cells formed therein. Each of the ammunition cells is alignable with the train axis of the weapon so that an ammunition round may be loaded into the cell, and is also alignable with a transfer axis that is off-set from the train axis. A pivoting cradle is also provided which can be aligned with the transfer axis. When the ammunition cell containing an ammunition round is aligned with the transfer axis and the cradle is also aligned with the transfer axis, the ammunition round may be transferred from the ammunition cell to the cradle. The cradle may then be swung into position proximate the breech of the weapon, the ammunition round rammed into the breech, and the weapon fired. The ammunition transfer system of the present invention is suitable for handling any type of ammunition including separate, semi-fixed, or fixed ammunition, and may also be used to handle rocket propelled or precision guided munitions. It is anticipated that the ammunition handling system of the present invention, when used with a major caliber gun, may enable firing rates of ten rounds per minute and more.
Thus, the invention may be characterized in one embodiment as an ammunition transfer system for a weapon having a carriage. The system comprises an ammunition hoist positioned along a charging axis, a cradle operably coupled to the carriage and capable of being positioned along a transfer axis, and a carrier operably coupled to the carriage. The carrier has at least one cell adapted to receive an ammunition round. The cell is controllably alternately positionable along the charging axis to receive the ammunition round and along the transfer axis to discharge the ammunition round to the cradle.
The invention may also be characterized as method for loading a weapon, the weapon being rotatable on a carriage. The method may comprise first providing ammunition transfer system comprising an ammunition hoist disposed along a charging axis, a cradle operably coupled to the carrier and capable of being positioned along a transfer axis, and a carrier fixed to the carriage, the carrier having at least one cell adapted to receive an ammunition round. The cell is selectively alternately positionable along the charging axis to receive an ammunition round and the transfer axis to discharge the ammunition round to the cradle. The method also includes the steps of positioning the carrier so that the cell is aligned with the charging axis, loading an ammunition round in the cell, positioning the carrier so that the cell is aligned with the transfer axis, positioning the cradle along the transfer axis, and transferring the ammunition round from the cell to the cradle along the transfer axis.
The invention may also be characterized as a weapon with an ammunition handling system. The weapon comprises a carriage, a barrel mounted on the carriage and positioned along a loading axis, an ammunition hoist positioned along a charging axis, a cradle operably coupled to the carriage and capable of being positioned along a transfer axis and along the charging axis, and a carrier attached to the carriage and having a plurality of ammunition cells adapted to receive an ammunition round. Each of the plurality of ammunition cells is positionable along the charging axis to receive the ammunition round and along the transfer axis to discharge the ammunition round into the cradle.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.